# Master Lock Portable Key Safe with Shackle, Medium

Source: https://www.ranked10.co.uk/home/best-key-safes/master-lock-portable-key-safe
Ranked #4 in "Best Key Safe 2026: 10 Ranked, and the Numbers That Don't Add Up": https://www.ranked10.co.uk/home/best-key-safes

- Price: £29.40 (checked on Amazon UK on 2026-09-19)
- Amazon rating: 4.3 from 1,626 ratings
- Buy on Amazon: https://www.amazon.co.uk/dp/B000JTIX10?tag=ranked10-21

The Master Lock 5400EURD (the spec panel also lists 5400D as the model number) is the odd one out in this list: it is not a box you screw to a wall. It is a metal lock box with a shackle, sold at £29.40, rated 4.3 out of 5 from 1,626 ratings, and ranked first in Amazon's Key Cabinets category and 41st in DIY & Tools. It sits at number 4 here.

Where the other listings contradict themselves on size, this one largely holds together — and that is the finding. The title says 90 x 157 x 40 mm; the fourth bullet says 15.7 cm x 9 cm x 4 cm. Same box, same numbers. But that same bullet calls the cavity "large" and then measures it: 7.4 cm x 6.8 cm x 3 cm, or roughly 151 cm³ of interior against 565 cm³ of exterior. The copy says the four-digit dial offers "thousands" of combinations; four digits actually give 10,000, so here the marketing understates rather than inflates. The rating breakdown the page shows (67 five-star, 16 four-star, 5 three-star, 4 two-star, 8 one-star) adds to exactly 100, which puts 12 of it at one or two stars. Everything on this page comes from the Amazon listing itself, not from any test of our own.

## Specification

| Field | Value |
|---|---|
| Price | £29.40 |
| Rating | 4.3 out of 5 from 1,626 ratings |
| Model | Master Lock 5400EURD (model number listed as 5400D) |
| Exterior dimensions (H x W x D) | 15.7 cm x 9 cm x 4 cm, shown in the title as 90 x 157 x 40 mm |
| Interior dimensions (H x W x D) | 7.4 cm x 6.8 cm x 3 cm |
| Lock type | Mechanical code lock, resettable four-digit combination |
| Special features | Anti-Corrosion, Portable, Resettable, Weather Resistant |
| Best Sellers Rank | 1 in Key Cabinets (DIY & Tools), 41 in DIY & Tools (as listed) |

## Questions people ask

**How many combinations does the Master Lock 5400EURD allow?**

It uses a resettable four-digit combination dial. The listing calls this "thousands of personalized combination code options"; four digits give 10,000 possible codes.

**How much fits inside the Master Lock 5400EURD?**

The listing gives interior dimensions of 7.4 cm x 6.8 cm x 3 cm (H x W x D), about 151 cm³. The bullet that gives those figures also calls it a "large internal cavity" for multiple keys.

**Does the Master Lock 5400EURD need to be screwed to a wall?**

No fixings are listed. It is described as a portable lock box with a shackle, designed to fit over a door knob, and the reviews mention it around railings, a hand rail and inside a gas meter cupboard.

**Can the Master Lock 5400EURD be used outside?**

The listing says indoor and outdoor use, with a shutter door to protect the combination dials from weather, and lists weather resistant and anti-corrosion among its features. No water resistance rating is given.

**What warranty comes with the Master Lock 5400EURD?**

The listing states a limited lifetime warranty against mechanical failure.

**How is the Master Lock 5400EURD rated?**

4.3 out of 5 from 1,626 ratings. The breakdown on the page (67 five-star, 16 four-star, 5 three-star, 4 two-star, 8 one-star) adds to 100, so 12 of it sits at one or two stars.